DEOILING OF CRUDE LECITHIN WITH PROPANE

The complete removal of extractant from deoiled lecithin is very diffi cult if acetone has been applied. Furthermore, some reaction products are formed during this process. These products have a negative effect on the quality of the produced lecithin. The deoiling of crude lecithi n with propane does not have such disadvantages. The new developed pro cess differs from the ''classical'' supercritical gas extraction by an operating pressure which is an order of magnitude lower (about 40 bar ) than in conventional gas extraction. It is therefore called Low Pres sure Gas Extraction (LPGE). In order to determine the suitable conditi ons for a continuous countercurrent extraction, phase equilibria were measured in the system lecithin/soybean oil/propane in relation to tem perature and pressure. Experiments in a pilot plant show that this pro cess can be realized with commercially favorable costs. The produced l ecithin is practically oil-free and the oil is lecithin-free.